CVE-2026-73629

HIGH CVSS 4.0: 8.4
Updated Aug 13, 2026
S9Y
Parameter Value
CVSS 8.4 (HIGH)
Affected Versions before 2.6.0
Fixed In 2.6.0
Type CWE-918 (Server-Side Request Forgery (SSRF))
Vendor S9Y
Public PoC No

Serendipity before 2.6.0 contains a server-side request forgery vulnerability in the serendipity_url_allowed() filter that fails to block hex-encoded IPv4 addresses, IPv6 literals, and link-local ranges. Authenticated users with adminImagesAdd permission can bypass the filter using alternate address formats to request internal services and retrieve response bodies through the public uploads directory.

Attack Parameters

Attack Vector
Network
Can be exploited remotely
Attack Complexity
Low
Easy to exploit
Attack Requirements
None
No additional conditions
Privileges Required
Low
Basic privileges needed
User Interaction
None
No user interaction needed

Impact Assessment

Confidentiality
High
Complete data leak
Integrity
Low
Partial data modification
Availability
None
No disruption

CVSS Vector v4.0

Vulnerable Products 1

Configuration From (including) Up to (excluding)
S9y Serendipity
cpe:2.3:a:s9y:serendipity:*:*:*:*:*:*:*:*
2.6.0